LG2A

Laboratoire de Glycochimie, des Antimicrobiens
et des Agroressources UMR 7378 CNRS

UMR 7378 CNRS

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  • Tutelle du CNRS
  • Tutelle UPJV

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Actualités et Publications

Recherchons candidat(e)s pour un poste de CR au sein de notre unité,

sections possibles sont la 11, 12, 13 et la 16, dépendant de l’expertise du candidat / de la candidate avec qui nous allons construire le projet.

Quelques thèmes (non exclusifs) :
- méthodologie en glycochimie, en chimie durable (mécanosynthèse),
- polysaccharides/polymères bio-sourcés,
- assemblages supra-moléculaires,
- modélisation moléculaire...
Le recrutement CNRS étant extrêmement compétitif, une ou plusieurs expériences post-doctorales et un très bon nombre de publications sont requis.

Graphene quantum dots: From efficient preparation to safe renal excretion,

Hadad, C.; González-Domínguez, J. M.; Armelloni, S.; Mattinzoli, D.; Ikehata, M.; Istif, A.; Ostric, A.; Cellesi, F.; Alfieri, C. M.; Messa, P.; Ballesteros, B.; Da Ros, T.

Nano Research 2020.

Carbon nanomaterials offer excellent prospects as therapeutic agents, and among them, graphene quantum dots (GQDs) have gained considerable interest thanks to their aqueous solubility and intrinsic fluorescence, which enable their possible use in theranostic approaches, if their biocompatibility and favorable pharmacokinetic are confirmed. We prepared ultra-small GQDs using an alternative, reproducible, top-down synthesis starting from graphene oxide with a nearly 100% conversion. The materials were tested to assess their safety, demonstrating good biocompatibility and ability in passing the ultrafiltration barrier using an in vitro model. This leads to renal excretion without affecting the kidneys. Moreover, we studied the GQDs in vivo biodistribution confirming their efficient renal clearance, and we demonstrated that the internalization mechanism into podocytes is caveolae-mediated. Therefore, considering the reported characteristics, it appears possible to vehiculate compounds to kidneys by means of GQDs, overcoming problems related to lysosomal degradation.

Physicochemical, foaming and biological properties of lowly irritant anionic sugar-based surfactants,

Bois, R.; Abdellahi, B.; Mika, B.; Golonu, S.; Vigneron, P.; Chagnault, V.; Drelich, A.; Pourceau, G.; Wadouachi, A.; Vayssade, M.; Pezron, I.; Nesterenko, A.

Colloids and Surfaces A: Physicochemical and Engineering Aspects 2020, 607, 125525.

Surface-active compounds derived from biomass, especially sugar-based amphiphiles, have received wide attention regarding their biodegradability, low toxicity and ecological acceptability. Compared to nonionic sugar-based surfactants, the anionic ones show significantly better solubility, higher surface activity and foaming performance. Thus they are largely used in personal care formulations and many technological applications. However, anionic surfactants are well known to induce skin and eye irritation. In this study, three sugar-based anionic surfactants, bearing a lipidic chain grafted to the anomeric position of a monosaccharide (glucose or xylose) and a sulfate group on the primary hydroxyl, were synthesized: 6-O-sulfo-N-(β-d-glucopyranosyl) dodecanamide (GlcNC12S), N-dodecyl-6-O-sulfo-d-gluconamide (GlcCC12S) and N-dodecyl-6-O-sulfo-d-xylonamide (XylCC12S). These molecules were investigated in details for their self-assembling behavior, foaming properties and biological ef7452fects. All their properties were compared to those of two commercially available anionic surfactants, sodium laureth sulfate (SLES) and sodium dodecylsulfate (SDS). Results revealed that the three anionic glycolipids show surface properties and foaming behavior comparable to those of SDS. Furthermore, their cytotoxic and irritation potentials are significantly lower compared to commercial molecules, which make these renewable molecules potential candidates for replacement of petroleum-based compounds.

Insight on the Contribution of Plasmons to Gold-Catalyzed Solar-Driven Selective Oxidation of Glucose under Oxygen,

Golonu, S.; Pourceau, G.; Quéhon, L.; Wadouachi, A.; Sauvage, F.

Solar RRL 2020, 4, 2000084.

With the increasing concerns about pollution and reduction of energy demands, the use of solar energy to drive chemical transformations is becoming increasingly attractive. Within the context of sustainability, sunlight-driven organic transformation of biomass feedstock, such as free carbohydrates, to obtain high added-value products is an important topic in which the recent progress should contribute to the development of solar biorefineries. Among the variety of photocatalysts, gold nanoparticles (NPs) loaded onto large bandgap semiconductors represent the state of the art. Such catalysts are known to accelerate the targeted reaction upon plasmonic excitation. In addition, as noble metal NPs, they also hold an additional role related to surface catalysis, which has been exploited for aerobic oxidation of free sugars. Nevertheless, the respective contribution of each role during transformation is not well established. Herein, the enhancement of the O2-mediated oxidation of free sugars using Au NPs on CeO2 under standard air mass 1.5G illumination conditions is reported. The results highlight that the plasmonic contribution of Au NPs is totally annihilated and this enhancement stems solely from a thermal activation process induced by NIR radiation from standard white-light conditions.

First step to the improvement of the blood brain barrier passage of atazanavir encapsulated in sustainable bioorganic vesicles,

Nolay, F.; Sevin, E.; Létévé, M.; Bil, A.; Gosselet, F.; El Kirat, K.; Djedaini-Pilard, F.; Morandat, S.; Fenart, L.; Przybylski, C.; Bonnet, V.

Int. J. Pharm. 2020, 587, 119604.

The blood - brain barrier (BBB) prevents the majority of therapeutic drugs from reaching the brain following intravenous or oral administration. In this context, polymer nanoparticles are a promising alternative to bypass the BBB and carry drugs to brain cells. Amphiphilic cyclodextrins can form self-assemblies whose nanoparticles have a 100-nm-diameter range and are thus able to encapsulate drugs for controlled release. Our goal is to propose an optimized chemical synthesis of amphiphilic cyclodextrin, which remains a challenging task which commonly leads to only a low-milligram level of the high purity compound. Such cyclodextrin derivatives were used to prepare vesicles and to study their ability to vectorize a drug through the BBB. As a result, we introduced a convergent synthesis for a family of lipophosphoramidyl permethylated β-CDs (Lip-β-CDs) with various chain lengths. It was demonstrated that mixed vesicles comprised of phosphatidylcholine (POPC) and LipCDs were able to encapsulate atazanavir (ATV), a well-known protease inhibitor used as an antiretroviral drug against HIV. We highlighted that neo-vesicles promote the penetration of ATV in endothelial cells of the BBB, presumably due to the low fusogenicity of Lip-β-CDs.

Synthesis of defined oligohyaluronates-decorated liposomes and interaction with lung cancer cells,

Cano, M. E.; Lesur, D.; Bincoletto, V.; Gazzano, E.; Stella, B.; Riganti, C.; Arpicco, S.; Kovensky, J.

Carbohydr. Polym. 2020, 248, 116798.

In this work hyaluronic acid (HA) oligosaccharides with degree of polymerization (DP) 4, 6 and 8, obtained by enzymatic depolymerization of HA, were conjugated to a PEG-phospholipid moiety. The products (HA-DP4, HA-DP6 and HA-DP8) were used to prepare decorated liposomes. The cellular uptake of HA-DP4, HA-DP6 and HA-DP8-decorated fluorescently labelled liposomes was significantly higher (12 to 14-fold) in lung cancer cell lines with high CD44 expression than in those with low CD44 expression, suggesting a receptor-mediated entry of HA-conjugated formulations. Competition assays showed that the uptake followed this rank order: HA-DP8>HA-DP6>HA-DP4 liposomes. Moreover, they are capable of a faster interaction with CD44, followed by phagocytosis, than HA liposomes obtained from HA of higher molecular weight (4800 and 14800 Da). HA-DP4, HA-DP6 and HA-DP8-liposomes did not show cytotoxicity or inflammatory effects. Overall, we propose our new HA-DP oligosaccharides as biocompatible and effective tools for a potential drug delivery to CD44-positive cells.

Development of C-type lectin-oriented surfaces for high avidity glycoconjugates: towards mimicking multivalent interactions on the cell surface,

Porkolab, V.; Pifferi, C.; Sutkeviciute, I.; Ordanini, S.; Taouai, M.; Thepaut, M.; Vivès, C.; Benazza, M.; Bernardi, A.; Renaudet, O.; Fieschi, F.

Org. Biomol. Chem. 2020.

Multivalent interactions between complex carbohydrates and oligomeric C-type lectins govern a wide range of immune responses. Up to date, standard SPR (surface plasmon resonance) competitive assays have largely been to evaluate binding properties from monosaccharide units (low affinity, mM) to multivalent elemental antagonists (moderate affinity, µM). Herein, we report typical case-studies of SPR competitive assays showing that they underestimate the potency of glycoclusters to inhibit the interaction between DC-SIGN and immobilized glycoconjugates. This paper describes the design and implementation of a SPR direct interaction over DC-SIGN oriented surfaces, extendable to other C-type lectin surfaces as such Langerin. This setup provides an overview of intrinsic avidity generation emanating simultaneously from multivalent glycoclusters and from DC-SIGN tetramers organized in nanoclusters at the cell membrane. To do so, covalent biospecific capture of DC-SIGN via StreptagII /StrepTactin interaction preserves tetrameric DC-SIGN, accessibility and topology of its active sites, that would have been dissociated using standard EDC-NHS procedure under acidic conditions. From the tested glycoclusters libraries, we demonstrated that the scaffold architecture, the valency and the glycomimetic-based ligand are crucial to reach nanomolar affinities for DC-SIGN. The glycocluster 3.D illustrates the tightest binding partner in this set for a DC-SIGN surface (KD= 18 nM). Moreover, the selectivity at monovalent scale of glycomimetic D can be easily analyzed at multivalent scale comparing its binding over different C-type lectin immobilized surfaces. This approach may give rise to novel insights into the multivalent binding mechanisms responsible for avidity and make a major contribution to the full characterization of the binding potency of promising specific and multivalent immodulators.

Amide Synthesis by Transamidation of Primary Carboxamides,

Kolympadi Marković, M.; Marković, D.; Laclef, S.

Synthesis.

The amide functionality is one of the most important and widely used groups in nature and in medicinal and industrial chemistry. Because of its importance and as the actual synthetic methods suffer from major drawbacks, such as the use of a stoichiometric amount of an activating agent, epimerization and low atom economy, the development of new and efficient amide bond forming reactions is needed. A number of greener and more effective strategies have been studied and developed. The transamidation of primary amides is particularly attractive in terms of atom economy and as ammonia is the single byproduct. This review summarizes the advancements in metal-catalyzed and organocatalyzed transamidation methods. Lewis and Brønsted acid transamidation catalysts are reviewed as a separate group. The activation of primary amides by promoter, as well as catalyst- and promoter-free protocols, are also described. The proposed mechanisms and key intermediates of the depicted transamidation reactions are shown.



Laboratoire de Glycochimie, des Antimicrobiens et des Agroressources
UMR 7378 CNRS
10 rue Baudelocque
80039 Amiens Cedex
tel/fax : 33 (0)3 22 82 75 60
N° SIRET : 19801344300017